I'll second those comments about limiters or AGC (automatic gain control). Lots of good advice here. Meanwhile, to get the best possible results from the existing setup be sure to go into Control Panel -> Sound and click on the Recording tab. Check the properties for the input jack you are using. Some drivers will have a gain selection with values like 0, +10, and +20db. If you see a choice like this be sure you are set to 0 or whatever the lowest setting is.